There was a time, believe it or not, when most NFL playing surfaces didn’t serve as three-hour infomercials for lawn care or low-maintenance FieldTurf. When gridirons crisscrossed baseball diamonds. When the only “heating systems” came not from miles of underground pipe but that big orange ball in the sky.

When Bud Grant and his four Grey Cup trophies came south from Winnipeg to coach the Vikings in 1967, they brought with them a pre-global warming savviness that often helped the Vikings cope with elements that were out of the NFL’s control at the time.

“We used to carry broomball shoes,” said longtime Vikings equipment manager Dennis Ryan. “That was Bud’s deal in Canada. If the field iced over, guys would put broomball shoes on. We didn’t wear them often, but we did in Boston when they were the Boston Patriots and games were at Harvard Stadium.”

Fields have evolved immensely, but even in mid-November 2018, NFL playing surfaces were a topic of discussion this week.

Nationally and internationally, the league’s eye was blackened when it was forced to move — on six days’ notice — the season’s marquee prime time game from Mexico City because of horrendous field conditions at Azteca Stadium. Diverting the 9-1 Chiefs and the 9-1 Rams to Los Angeles is a blow to a league itching for global domination.

Locally and regionally, the Vikings head to Soldier Field, a proverbial 100-yard box of chocolates made even more unpredictable by a 7:20 p.m. kickoff.

“I don’t like to be critical of surfaces, but it’s normally not one of the best,” Vikings safety Harrison Smith said. “It’s been pretty consistent that way.”

The Chicago Park District oversees Soldier Field. The Bears are but one attraction that uses the facility, so the sod can get pretty sad as the season ages.

Sometimes, that field is re-sodded two or three times a season. Many times, it’s a patch job between the hash marks. This year, Bears General Manager Ryan Pace urged a total re-sod, which was done about two weeks ago.

There were no issues or complaints after last week’s game against the Lions. A rarity for mid- to late-season games on a field that players routinely rate among the five worst in the league.

The Vikings expect good conditions but are prepared for the worst. Each player will have at least three pairs of cleats on hand. One will be the molded bottoms, which players wear indoors and most prefer. The other two pairs will be seven-stud shoes, one with five-eighths-inch studs and one with half-inch studs.

The team also carries three-quarter-inch studs that can be put on quickly with a drill. But that length hasn’t been used in years because rarely does a field in today’s NFL get that sloppy.

“You decide in pregame how it feels,” Smith said. “I’ve worn both the moldeds and the [five-eighth-inch studs] in Chicago. What I don’t get is why they don’t make studded shoes with more than seven studs. The moldeds are shorter, but there’s [16] of them and they’re all over.”

Footwear has been a valuable piece of equipment since the league’s early days. In fact, the 1934 NFL Championship game is known as the “Sneakers Game.”

The Bears and Giants were playing on a frozen field at the Polo Grounds in New York. Legend has it that Ray Flaherty, Giants captain and assistant coach, mentioned to head coach Steve Owen that he once played in sneakers to get better traction on a frozen field.

Owen had a friend named Abe Cohen, who worked the sidelines during Giants games. Cohen went way back with Chick Meehan, the coach at Manhattan College.

Cohen had the keys to the Manhattan gym. He hopped a cab, fetched about a dozen pairs of sneakers and got back to the Polo Grounds in the second half.

The Bears led 13-3 entering the fourth quarter. The Giants put the sneakers on, scored 27 fourth-quarter points and won 30-13.

Eighty-four years later, Vikings receiver Adam Thielen was asked about the challenges that receivers and defensive backs face when it comes to keeping their feet under them at Soldier Field.

“It’s equally hard on both of us,” he said. “It’s just who’s not going to slip on that play. Because if you slip and he doesn’t, it’s going to be a bad play.”

Mark Craig has covered college or pro football for 27 of his 31 years as a sports writer at the Canton (Ohio) Repository (1987-99) and Star Tribune. He is in his 24th season of covering the NFL. He is one of the 48 selectors for the Pro Football Hall of Fame.